In chemotherapy treatment, the level of treatment is usually determined by the level of chemotherapy that the patient can withstand, not the amount that is necessary to kill all tumor cells. We will focus drug-coated magnetic nano-particles to tumors by dynamic control of external magnets, allowing focused (high-concentration) treatment at the tumor with low levels of chemotherapy in the rest of the body. Magnetic nano-particle drug delivery already exists but it is limited to tumors near the skin surface. In this R21 grant we aim to show that it is feasible to precisely control magnetic fields to focus chemotherapy nano-particles to tumors deep inside the body - our goal is to show proof-of-concept. Hence deep-focusing will be experimentally demonstrated in a simple vasculature phantom (as recommended by reviewer 1 in our first submission). PUBLIC HEALTH RELEVANCE: This research would allow targeted chemotherapy. It would allow confinement of drugs at deep tumors with a low concentration of drugs in the rest of the body, thus enabling more effective cancer treatment but reducing life-threatening chemotherapy side effects.